Making sure children have safe access to technology requires the participation of hardware vendors, app developers, service providers, educators, industry leaders, and the media. But ensuring the safe use of tech products by children begins and ends with parents.

They're the ones who gauge how much technology the child can handle, who establish the parameters for the child's use of computers and phones, and who keep a close-but-not-too-close watch on how the child is using the technology.

Monitoring your children's use of the family computer is easier than keeping tabs on their phone use simply because the computer is out in the open -- or should be, according to the advice of experts. Implementing parental controls on smartphones is trickier because kids use the devices out of your sight for the most part.

But smartphones also offer tremendous safety benefits to parents. They can make it easier to know where your child is at a glance, and they let parents contact their children at almost all times. Here's how to ensure you and your children realize the benefits of smartphones and avoid the devices' many dangers.

How much phone does your child need?
Is your nine-year-old mature enough to handle having his or her own phone? Twenty percent of parents say "yes," according to a study (PDF) conducted by Bridgewater University researcher Stephanie Englander, as cited by CNET's Dara Kerr in an Internet & Media post from last April.

The need to educate children on the proper use of cell phones is driven home by another finding of the survey: while incidents of in-school bullying decline as children move from elementary school to middle school and high school, cyberbullying increases as children get older, according to the study.

The next determination is whether the child is willing and able to adhere to the restrictions you place on their use of the phone. Keep in mind that kids are much more likely to send text messages than to make voice calls or send e-mail: a recent Pew Research Center survey found that the average number of texts sent by teens each day increased from 50 in 2009 to 60 in 2011. For some parents, regulating their child's phone use will require a crash course in texting technology.

Among Common Sense Media's tips for responsible texting are allowing texts only at specific times (no texting at the table, no texting until homework's done, and no texting after 9:00 p.m.) and monitoring the texts your child sends and receives.

I admit to being troubled by parents spying on their children's communications. If a child can't be trusted to use a technology responsibly, they shouldn't have access to it at all. Still, if you tell your child you will on occasion review their texts, that may be deterrent enough to prevent inappropriate texting.

On the other hand, kids will be kids, and the potential dire consequences of underage sexting can't be downplayed. As with so many aspects of parenting, the key is to keep the channels of communication open and to be aware of what your child is up to. It's just part of a parent's job.

Rules of thumb for age-appropriate phone use
When it comes to rearing children, hard-and-fast rules rarely apply. The current consensus of child-safety experts is that children shouldn't be given their own phone until they reach age 11, they shouldn't have a phone with a camera and Internet access until age 13 at the earliest, and they shouldn't have unlimited access to texting and the Internet until age 15 or 16.

Once you decide the time is right for your child to have a phone, you have to figure out which type of phone is best for them. The Pew Research Center's Teens, Smartphones & Texting report published last March found that 23 percent of children between the ages of 12 and 17 have smartphones, which increases to 31 percent of kids between ages 14 and 17.

Since children generally want the same phone features as adults, it's not a surprise that smartphones are the first choice of most teens. In addition to the access and usage controls built into the phones themselves (and which kids may be adept at overriding), most cell carriers offer to block phone-based purchases and filter content for free. Many companies also provide fee-based services that give parents more options for controlling and monitoring their child's phone use.

For example, AT&T's $5-per-month Smart Controls let you limit on-phone purchases to a set amount each month, block numbers, restrict the time the phone can be used, and set a monthly cap for texts and data transfers. Verizon's $5-per-month Usage Controls are similar and add the ability to block contacts and designate trusted contacts.

Your child may be better served by a prepaid phone designed specifically for youngsters. Kajeet offers plans from $5 a month to $50 a month, and offers phones priced from $30 for an LG 102 to $400 for a Samsung Conquer Android phone. Likewise, Firefly's mobile phones for kids start at $50, and the service's plans range from $5 to $65 a month.